* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}
body {
  color: white;
  background: #1e1e1e;
}
#html {
  padding: 20px;
  word-break: break-all;
}
#div {
  position: fixed;
  top: 20px;
  left: 50%;
  transform: translateX(-50%);
  transition: all 1s;
}

@media (max-width: 500px) {
  #html {
    height: calc(100vh - 220px);
    overflow: auto;
  }
  #div {
    position: relative;
    top: 0;
    padding: 20px;
  }
}
